Rooks beak

H Vivienne

I can't say I've ever noticed a thickening of the bill itself. The gular pouch extends extends quite a way beneath the lower mandible. It can enlarge considerably as they feed.

For example here's one before it starts feeding.

And here's one after it's been stuffing its face with the food being held in the pouch.

Rooks do live for quite a long time so I guess it's possible, as Alan has said, that there is some change in the bill with age but I really don't know.

Thankyou for your early reply. I notice the beak on this rook is dark. Mine all have white/light beaks. I believe they are rooks, as they appear to live in the rookery down the road. I have jackdaws too, and a smaller crow with dark beak, which is a carrion crow? The under part of the beak on your photo is the place where the part of the beak I have mentioned is exactly. But again it is a light coloured extension underneath on my rooks beak. And again, although some of the rooks have this, it is not all of them. I noticed too, that the bigger, younger looking birds don't appear to have this. It is almost like the older, slimmer birds have this "beak". Does not appear to affect them in any way.

Thankyou for your reply. I can identify with these photo's, looking at the rooks from a distance. But when I go in close, I can see the pouch, which appears to be definitely beak on the rooks here.
I should try and get a photo myself and post it (not too brilliant with technology!!!!) I will however take a closer look when I see my next rook with the "beak", especially as it may be a pouch, which I thought was a beak!!!
Thankyou.